Automated testing systems are used to test one or more electrical properties of electronic circuit(s) and device(s) by applying and monitoring test signals to the electronic circuit(s) or device(s) (hereinafter collectively referred to as a device under test (DUT)). In typical automated testing systems, one or more electrical test signals are provided to various nodes of the DUT and various outputs of the DUT are monitored. The test signals are typically applied from channel interface circuits that couple the test system to the DUT.
Conventional automated test systems typically contain a plurality of expensive data acquisition circuits to cover and test the wide variety of electronic circuits available. These data acquisition circuits can include a multi-channel analog output card(s), multi-channel analog input card(s), multi-channel digital output card(s), multi-channel digital input card(s), an oscilloscope card(s), a digital multimeter (DMM) card(s), a waveform generator card(s), a counter/timer card(s) and/or other suitable data acquisition circuits. In addition, many of the more sophisticated systems typically contain relay multiplexer/scanner cards that allow from four to sixteen programmable channel interface connections to be made at one time. Such testing systems require an increased number of components and cables, leading to increased size, cost and complexity of the test circuit design.
Thus, there is a need for a test circuit that provides the functional capability to test a wide variety of electronic circuits and devices and that includes the capability to provide any desired test signal on command without wiring changes that overcomes the above mentioned disadvantages.